**Describe the bug** When contributions are exported as a PDF, they are not sorted. **To Reproduce** - Go to https://indico.cern.ch/event/727938/manage/contributions/ - Select all contributions (takes some time!) - Click Export / PDF - The resulting file is not sorted by ID, nor by Title **Expected behavior** - Sorted by ID or by Title **Additional context** - Export as XLSX is sorted correctly by ID - Export as CSV is sorted correctly by ID